Carvalho, J.A., Rico, L., Santos-Guerra, A., Duarte, M.C., Romeiras, M.M. & Francisco-Ortega, J. (2018) Echium nervosum. Boraginaceae. Curtis’s Botanical Magazine 35(1), 63-74.
The Madeiran endemic Echium nervosum W.T. Aiton is illustrated based on plants grown at the Royal Botanic Gardens, Kew. Its ecology; phylogenetic and taxonomic placement, and conservation status are discussed. Twenty-nine species of Echium are endemic to the Macaronesian Islands and they represent one of the most spectacular and best known examples of adaptive radiation on oceanic islands.